1. Field of the Invention
The invention relates in general to a turboshaft engine, in particular a turbocompressor whose task is to supply the combustive air, under pressure, to the combustion chamber of an aircraft jet engine. It relates more particularly to a refinement strengthening the sealing of the junction between two subassemblies of such a machine, for example the junction under stress between a casing and a fixed blades support of the stator.
2. Discussion of the Background
In a turbocompressor of the type mentioned above, the stator is assembled with an outer casing. In order to prevent air leakages, two subassemblies, of the casing and of the stator, are shaped in order to define between them an annular chamber in which a seal is inserted. The latter bears against two annular walls that face one another and that are respectively part of the two subassemblies. The two annular parts in contact with the two subassemblies are applied against each other under axial stress. The stress can be expressed in millimeters, this value denoting the axial interference which would exist between the two subassemblies if the latter were not butted against one another under stress. Up to the present time, relatively low stresses have been used, traditionally of the order of 0.3 mm. More recently, this stress has been raised to 0.75 mm.
During certain operational phases, the chamber housing the seal can open under the effect of distortions due to heat. Moreover, during operation the seal undergoes distortions and wear which can even cause a loss of fragments which, driven by the pressure difference, become jammed between the facing surfaces of the annular chamber. These surfaces are damaged and the air leakages increase.